1. Technical Field
The invention relates to a collapsible container whose panels are interlocked and latched together at their respective edges when raised to thereby provide the assembled container with improved structural integrity.
2. Background Information
The prior art teaches collapsible containers featuring a generally square or rectangular bottom panel, and two pairs of opposed side panels (the latter sometimes being referred to as respective pairs of side and end panels or “walls”). Each side panel is pivotally connected to a respective bottom panel edge to move between a raised or “assembled” position in which each side panel is roughly perpendicular to the bottom panel, and a collapsed position. The side and bottom panels may include hinge components that conveniently permit the side panels to be “snapped” into place on the bottom panel, for example, by moving the basal edge of the side panel laterally (outwardly) relative to the bottom panel's peripheral edge.
The prior art teaches the placement of latch mechanisms on the adjacent edges of the raised side panels to thereby provide the container with greater structural integrity and improved vertical stacking capability when assembled. Generally, known latch mechanisms employ a resilient, cantilevered latch member that either is flush with, or projects from the nominal lateral edge or inner face of one side panel into engagement with a complementary recess defined in the opposed edge of an adjacent side panel. An example of a flush latch member is disclosed in U.S. Pat. No. 6,073,790. The projecting latch member and, often, the complementary recess respectively include a camming surface that cooperate to urge the latch member into engagement with the recess, whereupon opposed abutting shoulders on the latch member and the recess provide a “snap-in” engagement to secure the one side panel to the other.
When such a container is to be collapsed, the latch member is resiliently biased, for example, by application of finger pressure on a portion of its length so as to swing the latch member clear of the recess or striker, whereupon the one side panel may be pivoted free of the other side panel. One or more inwardly- or outwardly-directed flanges, defined on the opposed edges of the adjacent side panels, are often used in conjunction with such latches to prevent the overtravel of one side wall relative to the other. Interlocking webbing defined within one or more such flanges may be used to further enhance the torsional rigidity of the assembled container by preventing relative movement of one side panel edge along the other side panel edge.
Unfortunately, because the quality of the resulting interconnection between adjacent side panels is dependent upon the nature of the engagement between the opposed abutting shoulders of the latch member and the corresponding recess/aperture/striker, any damage to the exposed latch member, for example, during container assembly or use, including an unintended permanent bending of the latch member relative to the nominal edge of the side panel, may impair latch functionality. Moreover, when the latch member is integrally molded with the typically polymeric side panel, such outwardly-cantilevered latch members may exhibit a reduced service life due to a bending-induced failure mode.
Accordingly, what is needed is a latch mechanism for securely interconnecting the side panels of a collapsible container featuring a resilient latch member on one side panel proximate to an edge whose camming surface and associated abutting shoulder are neither located along, nor project beyond, the panel's edge, and further featuring an improved service life relative to known, outwardly-cantilevered latch members. It is also desirable to provide an inwardly-collapsible container that includes convenient, “snap-in” hinge components on the side and bottom panels while nonetheless better resisting the application to the side wall of external lateral loads.